1. Field of Invention
The present invention relates to hard disk drive assembly mounting on printed circuit boards, and in particular to hard disk drive assembly mounting on a portable computer motherboard.
2. Related Art
Consumers prefer portable computers that are both thin and occupy a small area (small footprint). Accordingly, portable computer manufacturers design machines so that internal components are closely positioned to one another. Portable computer major components typically include a large printed circuit board assembly (PCBA) including a printed circuit board (PCB) and attached integrated circuits (e.g., central processing unit and associated memory) that enable the computer to function ("motherboard"). This application refers to specific embodiments using motherboards, but persons skilled in computer design will understand that embodiments of this invention include PCBAs other than portable computer motherboards. Major components also typically include a hard disk drive assembly (HDDA) for information storage that is coupled to the motherboard. HDDAs typically include a hard drive assembly (HDA) (one or more rotating hard disks with associated read/write heads in a protected and filtered environment) and another printed circuit board assembly attached to the HDA that contains circuits controlling HDA operation and data input/output functions.
FIG. 1 is a plan view of a typical portable computer motherboard and HDDA layout. As shown, motherboard 10 includes several integrated circuit packages 12. Packages 12 contain the integrated circuit (IC) chips that perform basic functions that enable the computer to operate (e.g., central processor unit, random access memory, video controller, etc.). Motherboard 10 also includes a connector 14 used to connect a HDDA to selected ICs. As shown, motherboard 10 includes a cutout portion 16 in which HDDA 18 is positioned. HDDA 18 is secured to chassis 20 or other supporting apparatus using mounting brackets 22. HDDA 18 is electrically coupled to connector 14 via conventional interconnection 24 (e.g., flexible printed circuit or multi-wire ribbon cable; see e.g., U.S. Pat. No. 5,469,314 commonly assigned with the present application and incorporated herein by reference).
The area required by the motherboard and hard disk drive assembly combination limits size reduction of the portable computer. One possible way of reducing the area is to position the HDDA over or under the motherboard. However, HDDAs used in portable computers, such as HDDA 18, are typically approximately 9.5 millimeters (mm) thick. Thus positioning the HDDA vertically in relation to the motherboard results in a combination that is too thick. Furthermore, the flexible circuit connecting the HDDA to the motherboard contributes additional bulk to the HDDA and motherboard combination. What is desired is a way to reduce the area required by the HDDA and motherboard combination, while ensuring the minimum possible thickness.